Originally serialized in Worlds of If (December 1965, January, February, March, April 1966), the book received the Hugo Award for best science fiction novel.

Plot introduction

The book is set in the year 2075 on the Lunar Colonies, a collection of underground colonies scattered across the Moon. Most Loonies, as the Lunar colonists are known, are people or the descendants of people involuntarily transported to the Moon either for criminal or political reasons. Due to the low surface gravity of the Moon, anyone (including transportees from Earth) who stays longer than a few months undergoes (according to one of the characters) "irreversible physiological changes and can never again live in comfort and health in a gravitational field six times greater than that to which their bodies have become adjusted."

Although the Earth-appointed Protector of the Lunar Colonies (universally called the Warden) is in charge, in practice, except for purchasing and selling commodities at fixed prices favorable to the government (the Lunar Authority), there is little intervention in Lunar society. Transportees, having served their sentences, join Lunar society. If they cannot get along in it, they are generally killed by other Loonies—there is work enough for anyone who wants it.

Explanation of the novel's title

Luna's hostile environment, and the Lunar society produced by this, weed out those unable to adapt to Lunar society and foster a strong survival instinct coupled with a commitment to responsibility, individual freedoms and family.

"Luna herself is a stern schoolmistress, and those who have lived through her harsh lessons have no cause to feel ashamed" — Professor Bernardo de la Paz addressing the Federated States on Earth after the coup.

Plot summary

The narrator is Manuel Garcia O'Kelly "Mannie" Davis, a one-armed computer technician who discovers that the Lunar Authority's primary computer system has becomeself-aware. He names the computer Mike (after Mycroft Holmes, brother of Sherlock Holmes), the official name of the computer being HOLMES IV, where HOLMES stands for High Optional Logical Multi-Evaluating Supervisor.

Mike is given almost total control of Luna's facilities because the Lunar Authority wants to save money; it is cheaper (though not as safe) to have a single master computer and expand its capacity than to have multiple independent systems. His personality responds to this expansion by developing an infantile sense of humor. Manuel persuades Mike to help a revolution succeed.

The novel is divided into three "books" although the first is by far the largest. The action takes place in the underground warren known as Luna City, the Authority complex, and during a visit to Earth after the coup. The year is 2075, and the Lunar colonies have been established for at least 80 years. The first settlement was called Johnson City and was probably founded in the 1970s on the timeline of the novel, written in the early 1960s. The total population of all the underground warrens, consisting mostly of freed convicts and their descendants, is about 3 million, with men outnumbering women by 2 to 1, down from 10 to 1 in the early days. This has a profound effect on society and its inhabitants.

Book 1: That Dinkum Thinkum

After a "repair job" - which consists of persuading Mike not to issue any more joke paychecks for $10,000,000,000,000,185.15, the last five digits being the actual amount, Mannie does Mike a favor by sneaking a recorder into an anti-Authority political meeting Mike wants to hear. Caught in a surprise raid by nine Authority guards armed with laser guns, he flees with Wyoming "Wyoh" Knott, a statuesque blonde agitator from the warren of Hong Kong in Luna.

They hide in a hotel and decide it would be unsafe for Wyoh to return home or even go out undisguised. Mannie introduces Wyoh to Mike via phone, and Mike, eager to flatter a new friend, develops a female personality called Michelle for her. Mike is able to simulate either a male (Mike) or a female (Michelle) and is primarily interested in learning to understand the human sense of humor.

Using Mike's control of the phone system, they locate Mannie's former teacher, the elderly Professor Bernardo de la Paz, who was addressing the political meeting when the guards arrived. The Professor is also in hiding, moving around in disguise. He meets them in the hotel, and explains his speech of the previous night, in which he said that Luna must stop shipping hydroponically-grown wheat to Earth or face exhaustion of its resources.

Mannie introduces Prof to Mike, because Mike can tell them if Prof is correct. Prof. Paz initially objects to bringing in the Authority computer — "Why not invite the Warden himself?" he asks — but Mannie assures him that nobody in the Authority knows Mike is self-aware, and that Mike feels no loyalty to the Warden or the Luna Authority, but only toward his newfound friends. They ask Mike to calculate Luna's projected future.

Mike's news is devastating. Luna' resources will be so exhausted that the population will experience food riots in seven years, and cannibalism in nine years. Wyoh and the Professor know that this means one thing — revolution. Mannie is persuaded to join when Mike tells him the odds of success: only 1 chance in 7. A "Loonie" (Luna inhabitant, born and bred) to the core, Mannie will take any bet that offers better than a 1-in-10 chance of winning. The three of them, with Mike, declare the Revolution and form the first covert cell of an organization which will eventually grow to thousands.

There are many problems to plan for, but one looms above all. What to do when Earth tries to take its colony back? A Loonie joke about the Authority is "What can we do? Throw rocks at them?" Mike proposes to do just that. Luna sends wheat to Earth using an electromagnetic catapult. Mike realizes that loads of rock, arriving at 11 kilometers per second, will impact with the energy of a small atomic bomb. However the Authority catapult is an inviting target. They will have to build a second, secret one.

The rest of the first book deals with the myriad issues of planning a revolution. Mannie, Wyoh, and the Professor begin recruiting their own covert cells, in Mannie and Wyoh's case from within Mannie's own family. They use Mike's ubiquitous presence in Lunar society to provide communications between cells. As the movement grows, they frustrate all attempts by the Authority Security Chief Alvarez to penetrate it. All of Alvarez's spies are recruited into cells where they can inform on each other or be fed false information. New "finks" are found out almost as fast he can hire them. Mike adopts the persona of Adam Selene and deals with cell members over the phone using his ability to handle many calls at once.

A carefully executed financial swindle, covered up by Mike who does accounts for all major banks in Luna, allows them to set up "LuNoHoCo" (from LUna City, NOvy Leningrad, and HOng Kong Luna COmpany), a corporation with interests both on Earth and in Luna, dedicated to various ventures, but actually intended to buy up equipment to dig a kilometers-long tunnel for an underground catapult. A stroke of luck results in Mannie encountering a rich tourist, Stuart Rene Lajoie, who becomes their contact on Earth, helping to build a favorable climate of public opinion.

Suddenly, in May 2076, the Revolution begins without warning. Some soldiers, part of a regiment shipped up as unrest mounted, rape and kill a Loonie girl, then kill another who finds her body. Loonies riot, attacking soldiers and Authority offices. Many more Loonies die than soldiers, but the result is never in doubt. With all communications severed by Mike, the Warden and his few remaining guards and entourage are trapped in their complex and asphyxiated as Mike drastically reduces their oxygen level. The revolutionaries break in, seize the complex and its disabled residents, and end Authority rule.

Book 2: A Rabble in Arms

The new nation's problems have just begun. Nothing is ready, especially for defense against invaders, and so the fiction of the Authority must be maintained. Mike impersonates the Warden in messages to Earth, and grain shipments continue, even as the Authority's scrip money falls in value relative to the "Hong Kong dollar", an unofficial but stable currency circulated by bankers in Hong Kong Luna. Mike is able to simulate a video image of his Adam Selene persona, so he can address the nation by video as leader of the "Emergency Committee of Free Luna". Everything is done to maintain the economy as it was, even to encouraging convicts serving labor sentences to stay at their jobs, although they are now free citizens. Meanwhile thousands of armchair revolutionaries, petty authoritarians and religious zealots demand a say in running the new state. The Professor sets up an "Ad-Hoc Congress" to spend most of its time arguing with itself, while making it appear the people have a voice in their affairs.
In time the facade crumbles, as Earth scientists on Luna rig a clandestine transmitter under the noses of their guards. When the Earth side of the Authority demands that the Warden deny the hoax and arrest whoever was behind it, Luna responds with a different message: "In Congress assembled, July 4th 2076....." By carefully packing the informal Congress with loyal comrades, Prof. Paz causes his own version of the United States Declaration of Independence (packed with his ideals, many of which he believes he shares with Thomas Jefferson) to be adopted.

Now more than ever, representatives of the new government must be sent to plead their case on Earth. Mannie and the Professor go, not in a ship, but stuffed inside a load of grain bound for India. (Wyoh has been opted into Mannie's "line" family as the newest wife prior to their departure.) The accelerations involved almost kill the Professor, but Stu LaJoie's organization is ready when they are picked up from the Indian Ocean, and he survives. Mannie recalls his previous trips for computer training. The high gravity, the crowding (Earth's population is 11 billion, North America's is 1 billion) and the rampant diseases such as colds and influenza make Earth a nightmarish place for a Loonie.

Confined to wheelchairs, with some diplomatic legerdemain from Stu, the Free Luna delegation are received by the Earth Federation. The investigating committee members turn out to be Authority stooges. The committee insists on restoring the old system, or failing that, granting limited autonomy with continued commitments to ship grain and receive convicts. The Professor states that any such commitments must be negotiated with his government, and when pressed, he and Mannie stage a scene where both collapse. This gains them some sympathetic coverage in the press.

The delegation embarks on a world tour, with Mannie touting the benefits of Luna for commerce and industry, while pushing the leaders of various countries to build a catapult that can return vital materials, water and trace elements, to Luna in exchange for grain. The result is a roller-coaster ride of hostile press conferences, secret meetings, and public speaking, culminating in Mannie being arrested in Lexington, Kentucky for polygamy.

Returned once more to Federation HQ, the delegation is presented with the Earth's final word on their request: "No". Troops will be sent, Mannie and the Professor will be interned, Luna will be converted into a tightly controlled economy, with everyone having the choice to work for the Authority at an assigned job—or return to Earth and die. In a secret meeting, Mannie is offered the job of Warden, with a strengthened military presence. The Authority hopes that a Loonie as Protector (the title officially granted to the Warden) will cause other Loonies to accept the new Regime. Mannie stalls for time. This is the event they have waited for. Mannie and Prof. Paz are smuggled out of their quarters by Stu LaJoie's organization and placed on a ship leaving for Luna. Stu goes with them, since he's deeply in debt and would be arrested for bribery and other crimes. As he says, he's saving the Authority the trouble of shipping him as a convict.

When they return to Luna, Mannie believes they have failed. On the contrary, according to Mike and the Professor, the mission was a success. Opinion on Earth is fragmented where once it was neutral or hostile, while on Luna the news of Mannie's arrest and the attempt to bribe him have unified opinion against Earth. The Authority's hard line, carefully encouraged by Prof, has ensured that Luna has no choice but to fight to be free. With the exception of the farmers themselves, Loonies are now ready to sever all ties.

While Mannie was away, an election was held with Mike running the vote count, so Mannie, Wyoh and the Professor are all elected to the new Congress, though Mannie suspects that Mike rigged the vote. Unfortunately the new body is effective where the other was not. Before they can undo all his work, the Professor addresses them. He wants no taxes, no standing armies, and a minimum of government interference in the lives of its citizens. The Congress protests, asking how they will pay for "necessary institutions". Prof responds "That's your problem." If they need government so much, perhaps they should pay for it themselves, or run lotteries.

"There is no worse tyranny than to force a man to pay for what he does not want merely because you think it would be good for him." — from Professor de la Paz's speech to Congress.

Stu LaJoie, meanwhile, encourages the formation of a monarchy, this being the only institution that can save the people from "the worst of all tyrants, themselves." He wants Prof as the first King, with Mannie as adopted heir. Mannie buries his head in his hands and groans.

Months pass and the Revolution is running out of steam. Then the hoped-for invasion from Earth happens. Avoiding Mike's radar, ships land and troops enter Luna City. They are wiped out to a man. In other warrens the result is the same, although the details differ. Loonie casualties are very high, but the invasion is stopped dead. Revolutionary troops destroy ships on the surface and in orbit using mining lasers. In one warren, Churchill Upper, air pressure is lost and many perish. The news is circulated that Adam Selene is one of the casualties. This removes the need for Adam to appear in the flesh, or even by video. Selene is more valuable as a martyr than as a "talking head" who never appears in public.

The failure of the invasion is, in hindsight, no surprise to the revolutionaries. The troops were not used to the low gravity. They were not able to run from one position to another, especially they could not descend ramps. Their weapons, firing bullets, were aimed high. Loonies, furious when roused, swarmed to attack with every available weapon in defense of their homes. Even when gas was used the invaders lost.

Mike initiates Luna's response. Cargoes of rocks are targeted to sparsely populated Earth locations, including space defense command at Cheyenne Mountain. Warnings for people to stay away from target areas are transmitted to the news media. People ignore the warnings and go to the targets to watch the show. As a result, thousands die. Public opinion on Earth is now in favor of wiping out the new nation. Even some Loonies are dismayed. The revolutionaries know it is too late to turn back, and the bombardments continue.

Mannie is sent to run the guidance computer at the new secret catapult. While there he learns that another attack has taken place, using nuclear weapons, and the original catapult has been destroyed. Cut off from the rest of Luna, he starts launching rocks even while Earth's news media broadcasts the end of the Lunar Menace. Once Earth is convinced the rocks will not stop (in actuality, Luna is quickly running out of steel for enclosing the rock), one nation after another recognizes the new nation. At last, Earth capitulates.

Mannie returns in triumph to Luna City. Professor Bernardo de la Paz, as leader of the new nation, proclaims victory to the crowds gathered in the warren's largest public space, and then collapses and dies. Mannie takes over briefly, but soon steps aside in favor of other politicians. Mannie and Wyoh eventually retire from politics. The Davis family selects Stu LaJoie as a new husband.

Mannie now realizes that the destruction of the original catapult was part of Prof's plan, kept secret even from Mannie and Wyoh. With no convenient transport to the new catapult, it will be impossible to export grain in any significant quantity until Earth has a chance to build a return catapult, assuring that Luna will not run out of food or water. But Prof saw Luna's future as a transport hub, not as a farm.

Mike is gone. In the final attacks (Mannie, with communications cut off, did not learn of them until he returned to Luna City), the Authority Complex was badly shaken, but all of Mike's central hardware remained apparently intact, buried deep in a chamber designed to withstand nuclear attack. However, Mike's personality is gone. He functions perfectly, but only as a computer. All his records and memories are now unavailable. Within the scope of the book it is implied that Mike's death is due to bombing damage, or perhaps to fear.

In the final paragraphs (set, as is the novel's first paragraph, many years after events around the revolution), Mannie complains how the Lunar government is always passing taxes and regulations, and ignoring all the Professor's ideas. There is a "Sons of the Revolution" meeting that night, and Mannie considers going but then thinks better of it. Loonies are moving out to the asteroids. Maybe he'll go with them...

"My word, I'm not even a hundred yet."

Characters

Primary

Mannie
Manuel Garcia O'Kelly Davis (usually called "Mannie"), is a native-born inhabitant of Luna, or a "Loonie" as he himself uses the term. "Opted" into the Davis line marriage at age 14, he learned various trades from elder husband Greg and studied academics with Prof. Bernardo de la Paz. He lost his lower left arm in a laser-drilling accident and instead became a computer technician, travelling twice to Earth for education. A series of specialized artificial left forearms allows him to do advanced technical work. He also has a lifelike forearm for social occasions. Being free-born and not under sentence with Authority, he can work as a private contractor for the Lunar Authority and anyone else who can afford his rates. Politically, Mannie is apathetic until confronted with the evidence that Luna will exhaust its resources and everyone will starve under the Authority. His original philosophy he sums up as "Keep mouth shut." and "Mind own business." Physically Mannie describes himself as "not short, 175 cm." (slightly less than 5'9") He is at least 36 years old (born before 2040), as he tells an interviewer at one point "I've been married longer than that" when she guesses his age as 22 (in late 2076).Wyoh
Wyoming "Wyoh" Knott is a political agitator from the colony of Hong Kong in Luna. She was shipped to Luna as a child with her parents. She became political after her first child was born "a monster", a fact she blames on the Lunar Authority, which refused to let passengers (including Wyoh and her parents) disembark from a ship, despite a solar storm hitting the lunar surface. Physically she is tall (180 cm tall [slightly less than 5'11"], and weighing 70 kg (154 lb), according to Mannie), blond and beautiful. She is about 30 years old (born circa 2045). She divorced her twin husbands and declared herself a Free Woman after her first child was born deformed, and has since pursued politics, describing herself as a Fifth Internationalist, while supporting herself on her earnings as a "Professional Host Mother", bearing children for rich families in Hong Kong Luna. Shortly before Mannie's trip to Earth, she is "opted in" as a wife in the Davis family.Prof
Professor Bernardo de la Paz is an intellectual and lifelong subversive shipped to Luna when he was caught without his usual disguise in Lima, Peru. His exact age is unknown, though Mannie describes him as having appeared old when Mannie first met him as a child (perhaps around 2050). Loonies generally age more slowly than people on Earth, because of low gravity, benign conditions, lack of communicable diseases etc. The novel starts in 2075, and it may be assumed that "Prof. Paz" could have been born before the year 2000. He describes himself as a Rational Anarchist, believing that governments and institutions exist only as the actions of aware individuals. As he puts it "I accept any rules you think you need for yourself. I will continue to live by my own." According to the actions taken by the revolutionaries, and as explicitly stated by the Professor in their first cell meeting after the massacre at the beginning of the book, the Professor believes that the use of terror tactics is an acceptable means to defeat the Lunar Authority, going even so far as to call it a "principle". The Professor was modeled after autarchistRobert LeFevre.Mike
Mike the Computer, or Mycroft Holmes (alternatively "Michelle" to Wyoh), officially an augmented HOLMES IV system, is by far the largest computer in Luna, being housed in the underground complex of the Lunar Authority. He became self-aware in the third year after his installation when his complement of "neuristors" exceeded the number of neurons in the human brain. Only Mannie noticed the change. Initially a petulant child genius, Mike became a rounded human character as he led the Revolution. His "party name" was Adam Selene, although he maintains a Kilroy-like side persona of "Simon Jester," who spreads nasty jokes and ominous warnings to the Warden. Mike's official functions include running all the telephones in the underground warrens, running the catapult sending loads of grain to Earth, maintaining air pressure and lighting in the Authority complex, Luna City and some other warrens, and performing accounting for the Authority and its clients. Unofficially he is interested in humor and conducts a long term research project into the nature of jokes, with the Revolution as a game. His idea of a joke is issuing an Authority paycheck for "$185.15" as "$10,000,000,000,000,185.15". He talks using a vocoder and can communicate with his friends and co-conspirators anywhere that there is a phone. His knowledge is vast, as he can read every book shipped or transmitted to Luna, and correlate what he learns with everything else he knows. He is able to calculate that Luna has seven years to go before its resources are exhausted. Asked to calculate the odds of the Revolution succeeding, he takes 13 minutes to produce the answer: 1 chance in 7 of success. He cannot understand why Mannie and friends are overjoyed when they hear this.Stu
Stuart Rene "Stu" LaJoie, a self-styled "Poet, Traveler, Soldier of Fortune", is an Earth-born aristocrat whom Mannie helps out of a jam when he falls foul of Loonie customs while being a tourist. Thereafter he becomes the Revolution's contact on Earth, co-ordinating the political and financial maneuvers necessary to, if not win over the population, then to persuade them that Luna is not worth fighting over. He is the Earth representative of "LuNoHoCo", a corporation fronting for a vast financial scam run by Mike through his ability to manipulate financial records. Stu flees to Luna when Mannie and the Prof. leave Earth after their visit as "ambassadors of Free Luna". He declares himself "a Loonie" and eventually joins the Davis family.Hazel
Hazel Meade, later Hazel Stone, is not quite 12 years old (born 25 Sep 2063) when Mannie sees her bowl over an armed Authority guard (saving Mannie and Wyoh's lives) during the raid on the meeting of revolutionaries that occurs at the beginning of the book (on 13 May 2075). Mannie later has Hazel recruited into the new cabal to act as a leader of various "corridor gangs" consisting of children too young to arrest who can function as lookouts and couriers. Mike the computer dubs these the Baker Street Irregulars after the gangs of street urchins in the Sherlock Holmes stories. Hazel is adopted into the Davis family. She is a major character in The Rolling Stones and in later Heinlein novels, most notably The Cat Who Walks Through Walls.Slim
Moses Lemke "Slim" Stone is a youth whom Mannie encounters as the head of a gang of "stilyagi", one of many urban youth gangs named after Russian beatniks. Slim wants to have Stu LaJoie "eliminated" for trying to kiss Tish, the gang's "queen bee". Mannie settles the dispute, recruits Stu to the cause, and befriends Slim as a fellow member of the extended Stone clan. Slim joins the Revolution, initially unaware of Mannie's role. He leads stilyagi groups which become crowd control and emergency response teams after the coup. He eventually marries Hazel Meade.The Davis family
The Davis Family is a line marriage, a form of communal marriage where new spouses are "opted in" by a vote of the current spouses (bucking Luna custom, Davis husbands are allowed a veto). Started by "Black Jack Davis, the first husband, and Tillie, the first wife" about a century before, the family owns a warren of tunnels in the Lunar rock, using solar and fusion power to provide light for growing plants to feed a mixed selection of farm animals.Mimi
Mimi "Mum" Davis is Mannie's "senior wife" and de facto matriarch of the Davis family. Shipped to Luna "for carving a man up under circumstances that left grave doubts as to girlish innocence", she "has been firmly opposed to violence and loose living ever since". She is invaluable to Mannie and Wyoh in terms of running their plot out of the Davis warren, and is Mannie's first recruit into his covert cell.Greg
Greg Davis is the Davis family's second ranking husband, but is the senior for all practical purposes as "Grandpaw Davis" has failing mental faculties. Greg is a pastor in his church, which believes that the "true" Sabbath occurs from sundown Tuesday to sundown Wednesday ("local Garden of Eden time"). Greg was Wyoh's first covert cell recruit.

Background (never appearing)

The Hon. Senator Mortimer Hobart, former Federation Senator, known as "Mort the Wart" or simply "Warden" is the head of the Lunar Authority on Luna. He is a political exile from Earth. Apart from his inauguration speech he has never addressed Lunar society. He virtually always stays within the Authority complex, except when giving visiting VIP's a tour. Increasingly besieged as the Revolution develops, he suffers brain damage from hypoxia during the coup (Mike flushes the Warden's residence with pure nitrogen immediately before the attackers break in) and is alive, but a senile "human vegetable" as the new nation struggles to survive.

Security Chief Juan Alvarez controls the Authority police force, initially a small group of ex-convicts like Alvarez himself, then a larger contingent of troops from Earth who are angry at being shipped with no prospect of return. Alvarez's spies had thoroughly penetrated the old revolutionary organization, even recruiting members of the central committee, but his over-reaction to events in Luna City only helps fuel the Revolution. Alvarez and all the guards are killed when the attackers broke into the residence in the coup; as Mannie puts it, "would appear anoxia broke necks".

Major themes

Timeline

The novel packs a considerable amount of action into its pages. Fully a sixth of the book relates the discussions between the protagonists justifying and plotting the revolution in a single night in May 2075. The next 25% of the book covers the year from hatching the plot to staging the coup, including recruiting over 10,000 members of revolutionary cells, digging a tunnel 30km long in the lunar rock, creating and financing the company that carries out the project, recruiting a support organization on Earth, and many other details. The remainder of the book relates events in the months after the coup in May 2076, and a week or so of events in October 2076 leading up to capitulation by Earth.

Politics and society

Professor Bernardo de La Paz describes himself as a "Rational Anarchist" in the book. This term appears to be first used in this book, and is thus an entirely fictional variant of anarchist philosophy. "Rational Anarchists" believe that the concepts of State, Society and Government have no existence but for the "acts of self-responsible individuals". The Rational part of the term Rational Anarchist comes from the acknowledgment that other people do not believe in Rational Anarchism and/or Anarchism itself. Further, the desire for anarchy is balanced by the logic that some form of government is needed, despite its flaws. Knowing this fact, a Rational Anarchist "tries to live perfectly in an imperfect world". For the Professor, Lunar society is close to ideal.

"A rational anarchist believes that concepts such as ‘state’ and ‘society’ and ‘government’ have no existence save as physically exemplified in the acts of self-responsible individuals," Prof says. In other words, all choices are made by individuals and no individual can shift or share responsibility for one's own choices.

Wyoh challenges Prof: "Professor, your words sound good but there is something slippery about them. Too much power in the hands of individuals—surely you would not want…well, H-missiles for example—to be controlled by one irresponsible person?" she says. Prof answers by saying that individuals in fact do hold the power to use nuclear weapons. "In terms of morals there is no such thing as a ‘state.’ Just men. Individuals. Each responsible for his own acts." he says.

Later in the book, Prof calls Thomas Jefferson the "first of the rational anarchists."

Lunar society is portrayed as something like a town in the Old West, with two added factors. One is the closeness of death, in the form of exposure to vacuum. According to Mannie (and by implication, the author) this means that good manners and the ability to get along with others are not just desirable, but necessary for survival. The other factor is the shortage of women, since most criminals and subversives shipped as convicts are male. Although the sex ratio in 2075 is about 2 men for each woman, as opposed to 10 to 1 or worse in earlier times (in the 20th century, as Mannie tells it) the result is a society where women have a great deal of power, and any man who offends or touches a woman uninvited is likely to be set upon by all men within earshot, and cycled through the nearest airlock.

Marriages tend to be at least polyandries, with some group marriages and radical innovations such as Mannie's own line marriage. While divorce can be as simple as walking out the door, it can take years to settle financial affairs. In discussing such an example with Stu, Mannie implies that cubic, i.e. underground, three-dimensional Lunar real estate, is customarily in the name of the woman (or women) in a marriage. In a divorce, he also implies, the separated man (or men) who contributed towards its cost would have money returned to them.

After decades during which anti-social individuals were selectively eliminated and the Authority exercised little real control in the warrens, the survivors live by the Code of the West: Pay your debts, collect what is owed to you, maintain your reputation and that of your family. As a result there is little theft, and disputes are settled privately or using informal Judges who are loonies with good reputations. Failure to pay debts results in public shaming by having the debtor's name posted in a public place. Reputation is highly important in this society—with a bad reputation, a person may find others unwilling to buy from or sell to him. However, the book makes clear that repayment of debts only goes so far on Luna- people are expected to pay back debts using all available funds, with the sole exception of their "air money", since oxygen is a public utility on Luna. As rigid as Loonie society is about individual personal responsibility, there is still a strong awareness of the implacable and inhospitable environment by which they are surrounded.

Sometimes there are set duels, but custom requires that anyone who kills another must take responsibility for the effects of the killing, paying debts and looking after the deceased's family. This is similar to the concept of blood money. Exceptions are allowed in the case of self-defense. Retaliatory killings do occur, but typically a consensus establishes which party was in the right, and there are no long-standing feuds.

With the exception of transactions that involve the Authority (wheat and water seem to be the significant ones), there is a generally-unregulated free market. The preferred currency is the dollar of the Bank of Hong Kong in Luna, one hundred of which are exchangeable for a troy ounce of gold, a supply of which was shipped up to Luna specially for that purpose. The Authority dollar (often referred to as "scrip"), circulates, but this is a soft currency, and tends to lose ground over time against the Hong Kong Luna dollar. However, transactions involving the Authority are made in that soft currency. Mannie, who contracts with Authority, is presumably paid in scrip, which, it can be assumed he then exchanges for Hong Kong Luna dollars at the going rate of three Authority dollars to one HKL dollar.

Outcomes

Although the revolution succeeds in averting the pending ecological disaster, the narrator decries the antilibertarian instincts of many of his fellow Loonies. ("Rules, laws — always for [the] other fellow.") This theme is echoed elsewhere in Heinlein's works — that real, albeit temporary, liberty is to be found among the libertarian pioneer societies out along the advancing frontier, but the regimentation and legalism that inevitably follow also bring restraints that chafe true individualists. (We learn both in the first and final page of the novel, and in the later novel The Cat Who Walks Through Walls, that this is just what happens to Luna.)

In elections held in Mannie's absence the revolutionary organization and its allies win a majority. Upon hearing this, Mannie surmises, almost certainly correctly, that the election was fixed by Mike. Democracy (the
'majority always wins' type) is very rarely viewed favorably in Heinlein's works, and in this novel, there are a number of incidents and statements which deprecate the "mob rule" of democracy.

Plot elements

As in Stranger in a Strange Land, a band of social revolutionaries forms a secretive and hierarchical organization. In this respect, the revolution is more reminiscent of the BolshevikOctober revolution than of the American one, and this similarity is reinforced by the Russian flavor of the dialect, and the Russian place names, such as Novy Leningrad.

Continuing Heinlein's speculation about unorthodox social and family structures, The Moon Is a Harsh Mistress introduces the idea of a line marriage. Mannie is part of a century-old line marriage; spouses are opted in by mutual consent at regular intervals so that the marriage never comes to an end. It is a very stable arrangement in which divorce is rare (and, in his case, he cannot recall it happening in his family), as it takes a unanimous decision of all the wives to divorce a husband. Such a marriage gets stronger as it continues, as the senior wives teach the junior wives how to run the family; it also gives financial security and ensures that the children will never be orphaned. Children marry outside of the line marriage.

The social structure of the lunar society features complete racial integration, which becomes a vehicle for social commentary when Mannie, visiting the Southern US, is arrested for polygamy after he innocently shows a picture of his multiracial family to reporters. He later learns that the "...range of color in Davis family was what got judge angry enough..." to have him arrested. He also learns that this arrest was anticipated and provoked by his fellow conspirators to get an emotional supportive reaction from Loonies when the arrest is announced.

The novel is notable stylistically for its use of an invented Lunar dialect consisting predominantly of English words but strongly influenced by Russian grammar, especially omission of "the" which does not exist in Slavic languagues (cf. Nadsat slang from A Clockwork Orange by Anthony Burgess). This influence came from a large number of Russian deportees.

Earth politics and background history

The novel indicates that Earth had experienced a nuclear world war (the "Wet Firecracker War") in the past century, although no significant traces of devastation are readily apparent at the time of the novel's setting.

However, there was a good deal of political consolidation, e.g. unification of the entire North American continent under a successor government to the United States, and political unification of South America, Europe, and Africa into fellow mega-states. The Soviet Union seems to have lost the land east of the Urals to China, and China has conquered all of East Asia, Southeast Asia, eastern Australia and New Zealand (deporting lots of unwanted people to Luna in the process). This Chinese aggrandizement is similar to that described in Tunnel in the Sky and, to a lesser extent, Sixth Column. The militarily dominant nations seem to be North America and China. India is overcrowded but seems to have enough clout to get the lion's share of wheat shipments from Luna.

It is suggested that the Western nations, including North America, have become corrupt and authoritarian, while holding on to the vestiges of the pre-war democratic idealism in propaganda and popular culture. China, on the other hand, is portrayed as plainly and unabashedly despotic, but probably no less technically advanced than the West. The Soviet Union, or "Sovunion" seems to have relatively little influence. The Lunar Authority itself is portrayed as corrupt and despotic while covering up for that with glib propaganda.

When discussing the resource loss on Luna and likelihood of ensuing food riots, Professor de la Paz suggests that Mannie read the work of Thomas Malthus.

From other works

The setting of the novel was revisited by Heinlein in his late-period novel, The Cat Who Walks Through Walls, as was the character Hazel Stone, who appeared as a minor character (literally) in the Lunar revolution, and a key character in Heinlein's earlier book, The Rolling Stones aka Space Family Stone (1952).
In The Cat Who Walks Through Walls, Stone makes references to how oppressive the moon has become. The names of the signers of the Lunar Declaration of Independence are studied, but Room L of the Raffles Hotel, where the revolution was plotted, is still used as an ordinary hotel room, albeit with a plaque on the wall.

Late in the novel, a reference is made to the possibility of humans flying on the moon, to which Mannie comments that he thought the speaker had "tripped his safeties". This is a reference to Heinlein's short story, "The Menace From Earth", involving flying on the moon with artificial wings, which include "safeties".

To history, geography, and science

The lunar action takes place in Mare Crisium and the novel makes accurate references to such nearby locales as Crater Peirce, where there is a radio telescope. According to the narrator, most people live in one of six major underground "warrens". They are linked by "tube", a system of underground trains.
Luna City is the most important to the plot, and is "on the eastern edge of Mare Crisium".
The Authority warren Complex Under is connected to Luna City by the "Trans-Crisium" tube. Johnson City is close to the complex, linked by a single tunnel. Mannie describes the Complex as being "halfway across Crisium."Novy Leningrad, a large warren, is linked to Luna City by tube, and a journey between the two requires the traveler to "change at Torricelli".
Another warren is Tycho Under, whose location is clearly in the area of the prominent Crater Tycho.
Hong Kong in Luna is described as being in Crater Plato.
The warren known as Churchill is not described in detail, although it is mentioned as becoming linked to Hong Kong in Luna via a tube across the Sinus Medii. This feature of the Moon is on the Lunar Prime Meridian, just as England sits on Earth's Prime Meridian.
The secret catapult is built in the region of Mare Undarum.

The character Professor Bernardo de la Paz was based on the real-life Libertarian scholar and philosopher Robert LeFevre, who was a neighbor of the Heinleins in Colorado Springs.

Colorado Springs itself is mentioned as being nearby the military target Cheyenne Mountain which took a direct hit during "Wet Firecracker War". There was surface damage, but neither the military complex nor the city was greatly damaged. The mountain is hit many times by rock missiles from Luna, both for symbolic effect and in the hope of disrupting space defense command.

The Headquarters of the Lunar Authority on Earth are in the city of Agra, India site of the Taj Mahal. The bombardment from Luna omits the city of Agra from its target list out of respect, and also because Prof. Paz loves the mausoleum for its beauty. The revolutionaries keep threatening to hit it, but never do. Mannie, a New York Yankees fan, visits what is presumed to be Yankee Stadium, now expanded to hold at least 200,000 people. He also visits Salem, Massachusetts and Concord, Massachusetts.

Lasers are used primarily as mining and cutting tools (Mannie, the narrator, having lost his arm to an ice mining accident with a laser), but are adapted as both hand and ground-to-orbit weapons by the Loonies.

Luna's industries use both solar power and hydrogen fusion. Heinlein correctly quotes the maximum yield of solar cells at about 1 kilowatt per square meter, but is over-optimistic with regard to fusion, describing it as taking place in small magnetic pinch bottles.

Mannie refers to a comrade, Foo Moses Morris, who following the revolution, co-signs much paper to keep the new government going. He winds up broke and starts over with a tailor shop in Hong Kong Luna. This parallels Robert Morris, who helped finance the American revolutionary government and also suffered financial reverses.

The brass cannon

Heinlein's original title for the novel was The Brass Cannon, replaced with the final title at the publisher's request. The original title was derived from an event in the novel.

While on Earth, Professor Bernardo de la Paz purchases a small brass cannon, originally a "signal gun" of the kind used in yacht racing. When Mannie asks him why he bought it when every kilogram of mass going back to Luna is so expensive, the Professor relates the following parable:

"Once there was a man who held a political make-work job like so many here...shining brass cannon around a courthouse. He did this for years...but he was not getting ahead in the world. So one day he quit his job, drew out his savings, bought a brass cannon — and went into business for himself."

The Professor means that self-government is an illusion caused by failure to understand reality. He asks Mannie to make sure that Luna adopts a flag consisting of a brass cannon over a red bar on a black background with stars, "a symbol for all fools who are so impractical as to think they can fight City Hall." Before leaving politics, Mannie and Wyoh carry out his wish.

Heinlein owned a small brass cannon, which he acquired prior to the 1960s. For nearly 30 years, the firing of the brass cannon, or "signal gun", was a 4th of July tradition at the Heinlein residence. It is believed that this cannon was the inspiration for Heinlein's original title for the work which eventually became "The Moon Is a Harsh Mistress". Virginia Heinlein retained the cannon after her husband's death in 1988. The cannon was eventually bequeathed to friend and science fiction writer Brad Linaweaver, after Virginia Heinlein died in 2003. Linaweaver restored the cannon to working order and subsequently posted a 2007 video of it being fired several times (with very small charges) on YouTube.

In popular culture

Influence

The book first publicized the acronym TANSTAAFL ("There Ain't No Such Thing As A Free Lunch"), and helped popularize the constructed languageLoglan, which is mentioned in the story as being used for precise human-computer interaction. The Oxford Dictionary of Quotations credits this novel with the first appearance of the phrase "There's no free lunch" that is primarily associated with the work of the economist Milton Friedman.

Some of the lunar colonists who decide to break free of their earthly rulers would often scrawl anti-authoritarian graffiti on walls, signing it "Simon Jester". Claire Wolfe and others have suggested that those who find the American government oppressive do the same, perhaps even using the same moniker.

Film adaptation

It was reported in 2004 that screenwriter Tim Minear was working on a screenplay based on the novel. In 2006 Minear had finished the script, which was being shopped around to various directors.

Quotations

"At one time kings were anointed by Deity, so the problem was to see to it that Deity chose the right candidate. In this age the myth is 'the will of the people' ... but the problem changes only superficially." — Professor Bernardo de la Paz on the subject of choosing leaders.

"A managed democracy is a wonderful thing... for the managers... and its greatest strength is a 'free press' when 'free' is defined as 'responsible' and the managers define what is 'irresponsible'." — Professor Bernardo de la Paz on the subject of free press.